资料来源 : Webster's Revised Unabridged Dictionary (1913)

Logarithmically \Log`a*rith"mic*al*ly\, adv.
   By the use of logarithms.

资料来源 : WordNet®

logarithmically
     adv : in a logarithmic manner; "data plotted logarithmically with
           respect to time is shown in Figure 2"